Distraction Osteogenesis Study By Injection Of Calcium Alginate Hydrogel Containing HBMP2 Gene Transfected MSC

Objective To find a new way of the repair of bone defect by studying the biocompatibility and the bone formation in distraction osteogenesis (DO) region of human bone morphogenetic protein2 (hBMP2) gene transfected bone marrow stromal cells combined with calcium alginate hydrogel in bone tissue engineering.Methods Bone marrow stromal cells were obtained from the ciliac bone of healthy adult rabbits and cultured in Dulbeco's modied medium contained 10%fetal bovine serum. By means of lipofectamine, the expression of hBMP2 gene in these cells after transfection was determined by immunohistochemical analysis. Subsequently, the positive cells were screened out by G418,harvested and expanded, then cultured with or without calcium alginate hydrogel, at last observed with scan electron microscopy (SEM), MTT assay, the activity of alkaline phosphatase (ALP) and trypan blue stain.Then the complex of MSC transfected or not combined with calcium alginate hydrogel were injected into the region of DO at the late time of distraction period.Results The cultured MSC were proved to be transfected successfully throug immunohisto chemical analysis with yellow granules,light or dark, appearing in the plasma of the cells three days and 4 weeks after transfection.The calcium alginate hydrogel were well compounded with transfected MSC,improved the adhesion and proliferation of the cells,showed no adverse effect on the function of them.SEM showed that the cells in the material distributed equally with good shapes. Both MTT and ALP indicated no difference in statistic.After trypan blue stain nearly no blue cell could be seen.In vivo experiment...